sbase/grep.c
Hiltjo Posthuma 97fb4a1f9c grep: improvements
improvements:
- improve statuscode behaviour
  - don't exit if a file in a series fails. exit 2 if an error occured
    in a file series. don't exit if there is a read error (like: grep
     input file is a directory).
- use agetline instead of agets().

with the simple test: time seq 1 100000000 | grep 'a'
its 12 seconds (from 24 seconds) on my machine.

Signed-off-by: Hiltjo Posthuma <hiltjo@codemadness.org>
2014-06-01 18:02:01 +01:00

167 lines
3.0 KiB
C

/* See LICENSE file for copyright and license details. */
#include <regex.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "text.h"
#include "util.h"
enum { Match = 0, NoMatch = 1, Error = 2 };
static void addpattern(const char *);
static int grep(FILE *, const char *);
static bool eflag = false;
static bool vflag = false;
static bool many;
static char mode = 0;
static struct plist {
char *pattern;
regex_t preg;
struct plist *next;
} *phead;
static void
usage(void)
{
enprintf(Error, "usage: %s [-Ecilnqv] [-e pattern] pattern [files...]\n", argv0);
}
int
main(int argc, char *argv[])
{
struct plist *pnode, *tmp;
int i, n, m, flags = REG_NOSUB, match = NoMatch;
char buf[BUFSIZ];
FILE *fp;
ARGBEGIN {
case 'E':
flags |= REG_EXTENDED;
break;
case 'c':
case 'e':
addpattern(EARGF(usage()));
eflag = true;
break;
case 'l':
case 'n':
case 'q':
mode = ARGC();
break;
case 'i':
flags |= REG_ICASE;
break;
case 'v':
vflag = true;
break;
default:
usage();
} ARGEND;
if(argc == 0 && !eflag)
usage(); /* no pattern */
/* If -e is not specified treat it as if it were */
if(!eflag) {
addpattern(argv[0]);
argc--;
argv++;
}
/* Compile regex for all search patterns */
for(pnode = phead; pnode; pnode = pnode->next) {
if((n = regcomp(&pnode->preg, pnode->pattern, flags)) != 0) {
regerror(n, &pnode->preg, buf, sizeof buf);
enprintf(Error, "invalid pattern: %s\n", buf);
}
}
many = (argc > 1);
if(argc == 0) {
match = grep(stdin, "<stdin>");
} else {
for(i = 0; i < argc; i++) {
if(!(fp = fopen(argv[i], "r"))) {
weprintf("fopen %s:", argv[i]);
match = Error;
continue;
}
m = grep(fp, argv[i]);
if(m == Error || (match != Error && m == Match))
match = m;
fclose(fp);
}
}
pnode = phead;
while(pnode) {
tmp = pnode->next;
regfree(&pnode->preg);
free(pnode->pattern);
free(pnode);
pnode = tmp;
}
return match;
}
static void
addpattern(const char *pattern)
{
struct plist *pnode;
if(!(pnode = malloc(sizeof(*pnode))))
eprintf("malloc:");
if(!(pnode->pattern = strdup(pattern)))
eprintf("strdup:");
pnode->next = phead;
phead = pnode;
}
static int
grep(FILE *fp, const char *str)
{
char *buf = NULL;
size_t len = 0, size = 0;
long c = 0, n;
struct plist *pnode;
int match = NoMatch;
for(n = 1; (len = agetline(&buf, &size, fp)) != -1; n++) {
for(pnode = phead; pnode; pnode = pnode->next) {
if(regexec(&pnode->preg, buf, 0, NULL, 0) ^ vflag)
continue;
switch(mode) {
case 'c':
c++;
break;
case 'l':
puts(str);
goto end;
case 'q':
exit(Match);
default:
if(many)
printf("%s:", str);
if(mode == 'n')
printf("%ld:", n);
printf("%s", buf);
if(len && buf[len - 1] != '\n')
putchar('\n');
break;
}
match = Match;
}
}
if(mode == 'c')
printf("%ld\n", c);
end:
if(ferror(fp)) {
weprintf("%s: read error:", str);
match = Error;
}
free(buf);
return match;
}